1988 Oldsmobile Regency electrical failure

There are dozens of grounds on that car. the computer alone probably has four or five.
You need to run the basics.

All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.



Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.


2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.


3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.



Once you have determined which of these functions has dropped out,
you will know which system is having the problem.

Not true. If the car is running, I can wiggle or warm up fuses and ground connections to find one that kills the engine. Savvy? Testing while it is in failure mode is highly preferable, but not the only possibility.
My question requested the locations of the grounds. Not grounds for the taillights or dash lights or radio, since those all still work when the car dies, but for the engine operation. Feel free to exclude the ones in the computer.
Thanks.

Any of the ground locations could have multiple circuit connected to them.


Ground G100 (VIN C): RH Front Of Engine, On End Of Cylinder Head

Ground G103: RH Side Of Engine Compartment On Inner Fender Panel

Ground G104: LH Inner Fender Panel

Ground G105: LH Front Of Dash, On Brake Master Cylinder

Ground G108: LH Front Of Engine Compartment, At Horn

Ground G109: RH Front Of Engine Compartment, At Horn

Ground G202: At Top Of LH Shroud

Ground G203: Top Of RH Shroud

Ground G402 (98 Touring Sedan): RH Side Of Luggage Compartment, On RH Rear Wheelwell

Thanks for the good information Wrenchtech- very knowledgeable on procedure and tools. A mechanic had provided me with the exact tools you described to carry with me for when it fails, but it doesn't want to fail lately, so until it does I will be finding and wiggling those grounds, and heating fuses, to see if I can make it stop. Also will be listening for the whine of the fuel pump start-up when I turn the key on. Thanks again, Ralph

I have a 97 Regency and it would be going along fine and everything would die. I found that the ground was under the floor mat as you get into the drivers seat. I found it by accident as I would get in or out I would bump that mat area and hey presto it worked or stopped working when I moved the mat/carpet area. The connection had rusted and when I replaced that and got it grounded well again 2 years ago, I never have had any more unplanned stops. You are on the right track, find the ground and get it solid again. Alex

You have a '97 car. He has an '88 car. What does one have to do with the other? I gave him a complete list of every ground point in the car and under the mat is not one of them.

Thanks Wrenchtech, for your additional supervision & critique on this problem.